Snap gauge



May 1, 1951 J. B. sHocKLl-:Y 2,551,059

SNAP GAUGE Filed April 22, 1948 INVENTOR.

Patented May 1, 1951 UNITED STATES; `PATENTl OFFICE f A.2,551,059 'Y j sNArv GAUGE Joseph shek1ey,netmit, Mich. Application April 22, 1948, Serial No. 22,632- (c1. :aa-16s) 3 claims.

may be sim-ply and readily set to the particular" gage opening desired Without resort to screws or clamps as the adjusting or locking means and without necessitating the use of master gage blocks to check or determine the setting yof the e gage surfaces when adjustment is being effected.4

Commonly, snap gages are in the form of a C frame, one or bothof the legs of which are provided with slidable or screw-operated adjustable gaging members. In suchty-pes of snap gage means, such as clamping screws, are provided to .lock the adjustable gaging members in positions ,of setting.

Careless use of such gages can reduce the efliciency of the clamping means so as to distort `or, vary the gaging surfaces when the clamping is effected, or permit the adjustable elements to slip in use, and it is, therefore, an object of the present invention to provide an arrangement of `adjustable elementswhich does not call for the use of such clamping means and which provides at all times for an adequate support of the adjustable elements against slipping or other movement or angular variation which woulddetract from their accuracy. Y l

Furthermore, the adjustable type of snap gage hereinbefore referred to does not have self-contained means to positively determine the spacing or setting of the gaging elements, so that it is necessary to use a master gage or master blocks for insertion in the gap of the gage to determine the spacing of the elements as they are adjusted and set. This frequently means that the gage must be sent back tothe tool crib for setting, or the master blocks brought to the `bench for that purpose and afterward returned to their place of storage, all of which is unnecessarily time-consuming.

The present invention contemplates the incorporation in a snap4 gage of interchangeable pre-gaged and graded setting blocks or shims so concealed and arranged as to be easily inter- `changed to meet requirementsl while at the same time being thoroughly protected against loss, shifting, or access thereto 'of any material which may be deleterious to their proper functioning.

Still further, the said invention contemplates the use in the improved gage` of one or more slidable gage elements, of flat plate-like formation, housed in a slot or slots for sliding adjust- ,ment in `relation to thethroat of the gage together with a series of blocks or shims of graded thickness for selectivev arrangement behind each adjustable member to positively determine the vextent to which the forward working end of said member will extend into the throat of the gage t and thereby determine the gage opening. Where two ofY these adjustable members are utilized they are preferably arranged directly opposite Vone another, and the working surface of each member may be flat, wedge-shaped, or of other such form as may be necessary or 'desirable according to the .type of work to be checked.

It is further contemplated that one of the adjustable members may be divided to `provide two additional graded shims being provided for insertion behind the projected no-go portion of the adjustable element to determine the amount of advance of its working `surface beyond'that of the go portionof the adjustable element.`

Still further, the said invention contemplates the provision of removable holders for said slidable gage elements whereby said holders are de- .tachable and vinterchangeable on the legs of `the `caliper frame and, more Iparticularly, the invention contemplates that such holders be of a substantially angular S formation characterized by oppositely disposed recesses, one of which recesses is slidable over a corresponding web provided inthe leg of the caliper frame and the Aother recess accommodates the slidable gage member and its selected set of graded shims. 4It is proposed that the upper and lower ends of said recesses be overlapped by shoulders provided in Vthe leg of the ,caliper frame, at the upper and lower extremities of the web, for complete housing and protection of the parts housed in the said recesses. Y

Still further objects .or advantages additional lor subsidiary to the aforesaid objects, or result- 'ing from the construction or operation of the invention as it may be carried into effect, 'will become apparent as the said invention is herein- Y assises il 1 J an adjustable element to afford onset adjustments thereof of .001" to .015".

Similar characters of reference indicatefifsimilar parts in the several figures of the drawing.

A U-shaped caliper frame I is shown, thelegs of which are each slotted onfoppositesides, as at Il and l2, to provide a relatively thin web I3 terminating in a foot I8. The slot IIis'preferably materially shallower than is the slot I2,

for reasonswhich will become apparent, and this slotting of 1 thele'gs of'th'e caliperr frame 4provides'shoulders 'M -'I5 andIB-J-I'I dening the Ytop and bottomof the slots'as viewed inFigure u2 of the drawing.

A'pair 'of rectangular blocks, generally num- -lbered I9, "are provided, 'each'block being char- Sact'e'r'ized by' its being slotted from either end, as "atf25 "and "Z6, so thatthey 'are of an angular S lformation as viewed inplan, the slot 'being `proportioned to slidelover the' web I3 of thelcaliper frame; and the height of the 'blockis such `that its upper and lower surfaces will abut lthe shoulders IIIe-"I 5 and Ili-y I 'I,` respectively, of the vsaid 'caliper frame, whereby, when the "two l"blocks are positioned ori-'the webs I3 of the -caliiper Viframe, they will occupy the relationship In 'this position the innerrelation te one *enculer :and resist enyapr'essures *tending to increase this space, as-will be readily apparent. e

Located in the -s1etll2s efrene ofthe-blocks la i`s=a slidable plate 20operatingiaslaigaging v-i'nem- "ber, this plate being oflth'e saine `neig-litias'the sai'df-blck; Alar-id Vin i'lhe other-block 'i9 I show lI'iwo Asuch plates -2I land 212 rfeach of Y`vhalf vthe 'heightof the block, -an'd so totaling the "full height thereof land-similarly ``slidable in the slet Y'126 of'tha't particular block. These-'two plates Vv'arey also Y'adjustablegage meznbrsland the adjustmentof all of these 4lg'age members-120, 2 I,

inserts, Lvas will be explained.

is which 'includes the slot zs-lislhoused in YJthe *deeper recesses I2 of 'the legs Vof the *caliper frame, when the blocks are in position fasf'shown 'inFigureL so' that the shoulders 'I6 and I1 span the upper'and lower ends,.respectively, of the slots 26 and, therefore, lprotectively conceal jthe upper and lower ends of -the Isaid vslots as well Vas `provide guiding surfaces for the upper edges of the gage members "20andu22eand the lower edges of the gage members 20 and '2L Thus these .gage members are truly .guided for straight line adiustrnent witl'iY respect to-each other and are 'incapable of 'tilting or other an- "g'llar positional distortion.

y To provide for denitely predetermined adjustment of the gage 'niembersZ and 2-I-toward one another (so that y*the lgapYther@between'may "b'e #positively determined), I '-prov-"lde la ser-ies,

preferably eleven, of graded shims or plates adapted for selective insertion in the slots 26 behind the adjustable gage members. Thus, by providing, for example, eleven shims, generally numbered 23, of the dimensions .001", .002", .004", .008", .015, .020, .050, .100, .150", .200, and .200, totaling .750", any restriction of the gap between opposed gageV members may be obtained from .001" to .750 by simply select- -ingl those 'shims which will'addup to the amount of restriction'renuired 'and placing some of these so selected shims, according to desire, in the slots 26 behind each of the gage members 20 Il'IIS Thus, if the widest opening of the gage illustrated beconsidered as one and a half inches,

.it lwill be apparent that this opening may be reduced, in thousandths, to three-quarters of anlin'ch by using one or more of the shims 23 according to the reduction required. Accord- `in'gly, if 'theV gage/is -to berused to check work of 1.4 diameter, the' selected Ashims may be of the thicknesses of .050and .020, which we may vassume as inserted inthe block 'I9 behind the ygagemember -2I,:a'nd L001, .002, .004, .008",

Aand 'f.0-1`5 inserted'behind the Vgage element 20 'selectedfshims may bepla'ced behind only one f of the gage 1 elements, say' :2"0, theother. gage element :2 l simply @being 'fused .as a nxed yanvil 4in opposition to theIsaid-gage'elementZ I. .It'will be obvious thatonly V'one ofthe -igagefelements may fb'e adjustableifit'be'lpreferred tomake'the device in' that manner.

yW-hereuit lis desired 'to'provide tfgo or no-go "f-eature's in the ga'geto determine upper and lower limits of the work, the two-part adjustable gage member? I--"2\2 is utilized l"and one or' more of the 'shorter fshiins' (generally numbered fili in VFigure -5) VHare-insertedbehindl the '-portion-2l2 referred to,-so thatiit-is advanced beyond the portion 2l to ifa corresponding y extent.

T5008, any number of *thousandths of -advance from 1;001"''to .015 ""rnay be obtained by suitable 'combinationf thereof.

The 1s'turdihcss fof the arrangement described xwilrbel readily apparent as :aul gaging pressures are directed through the ff'blooks [-9 4directly 4agairis't the -ileg's of 4the caliper fr`ain'e,-'so 1 that `and vsnug fitting fwitho'utany undesirable Y play between the severalparts.

l12u-will also be'seen that where the blocks I9 Iare removable-which'is'the construction I prefer, various sets of-fblo'cks fma'y fbe set-up withthe required v'sliiihs in' position for l-o-iic'k interchange- "ability A'o1'ie'-vvith another, l Aso` that'- the gage Amay be utilized by a workman-'to'periorm several rvzlifii'erent'gaging 'operations-simply bysu-bstituting -theffrequired vblock assemblyiset up foreach operation.

-' It fw'ill 'befstill further apparent that thel setting @of Vthe l gage vmay be '-fquickly and positively changed and determined 'bysim-ply changing the -shixns so' that, when the movable lparts vare .again iirinly pressed into; assembledlposition, no further check-'bylm'aster blocks or otherwise-is -'desired to assurethat-the correct Igage opening #is secured.

"Scope 'Of "the I llWi-ng Claims Without tdeparting from-'the 'esseiitial''eatures of thesaid invention,

and it is desired that the specication and drawing be read as being merely illustrative of a practical embodiment of the same and not in a strictly limiting sense.

What I claim is:

1. In a C-shaped snap gage, a fixed body member having legs defining an open throat, an adjustable gage element, slotted holding means on one of the legs of said body member for slidably supporting said adjustable gage element whereby said element may be moved inwardly and outwardly of said throat, and a series of gradedthickness flat parallel-faced shims for selective insertion in the slot of said holding member between the base of said slot and said gaging element to positively determine by their thickness alone the position of advance of said element into said throat.

2. In a C-shaped snap gage, a fixed body member having legs defining an open throat, a pair of adjustable gage elements, slotted holding means on one of said legs for slidably supporting said adjustable gage elements one inwardly of said throat with respect to the other, a series of graded-thickness flat parallel-faced shims for selective insertion in the slot of said holding member said shims being of a length to extend between the base of said slot and both of said gaging elements, and a second series of shorter graded-thickness at shims for selective insertion in the said slot between said first mentioned shims and the innermost of said gaging an adjustable gage element, holding means slot-v ted from one end to engage the web of said leg and from the opposite end to slidably receive said adjustable gage element, and a series of graded at parallel-faced shims for selective insertion between the inserted end of said gaging element and the base of its respective slot to determine the projection of said element from said holding means into the throat of said body.

JOSEPH B. SHOCKLEY.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,138,438 Bailey May 4, 1915 1,397,189 Westerberg Nov. 15, 1921 1,489,577 Hanson i Apr. 8, 1924 

